Key lever and type bar assemblies of typewriters and like machines



E. C. BRACE 2,818,957 TERS KEY LEVER AND TYPE BAR ASSEMBLIES OF TYPEWRIAND LIKE MACHINES Filed May 25, 1954 2 Sheets-Sheet l Jan. 7, 1958 E. c.BRACE KEY LEVER AND TYPE BAR ASSEMBLIES OF TYPEWRITERS AND LIKE MACHINESI Filed May 25, 19

2 Sheets-Sheet 2 United States Patent KEY LEVER AND TYPE BAR ASSEMBLIESF TYPEWRITERS AND LIKE MACHINES Edward Charles Brace, Westgate-on-Sea,England Application May 25, 1954, Serial No. 432,254 Qlain s priority,application Great Britain May 27, 1953 Cl (Cl- 197- This inventionrelates to key lever and type bar assemblies of typewriters and likemachines, the object being to provide improvements therein.

An assembly of key lever and type bar for a typewriter or like machine,according to this invention, comprises a key lever, a type bar arid alink, the said link having a head at each end, the end of the key leverwhich is remote from the key thereon being adjacent the end of the typebar which is remote from the type thereon, the said adjacent ends beingprovided with recesses, and the said heads on the said link being seatedin said recesses for the link to provide an interconnection between thekey lever and the type bar. Preferably, the heads on the ends of thelink are cylindrical, and the recesses in the key lever and type bar arepart circular the arc thereof extending more than 180 degrees. The linkwith its heads may take the form of a dumb-bell. The recesses in the keylever and type bar have their axes disposed transversely of the lever orbar and are open at their ends, that is, at the sides of the lever orbar.

In the accompanying drawings,

Fig. 1 is a diagrammatic elevation of one form of key lever and type barassembly in accordance with this invention, showing the parts in therest position; and

Fig. 2 is a similar view, but showing the parts in the operative orprinting position.

Fig. 3 is a fragmentary plan view of the assembly shown in Fig. 1.

Fig. 4 is a diagrammatic elevation of a modified embodiment of theinvention.

Figs. 5 and 6 are diagrammatic elevations of a further modifiedembodiment of the invention, showing the parts in the rest" and printingpositions, respectively.

Referring to Figs. 1, 2 and 3, each key lever 11 is pivotally mounted,on a pivot rod or pin 12, in a housing segment 13, the said pivot beingintermediate of the key or front end 14 and the rear end 15 of thelever. Each type bar 16 is pivotally mounted, on a pivot rod or pin 17,in the segment 13, the said pivot 17 being located close to the bottomend 18 of the type bar, the upper end of said type bar carrying theprinting type mount 19. The bottom ends 18 of the type bars 16 aredisposed in slots 20 formed in a comb-like portion 21 of the segment 13,whilst the portions of the key levers 11 in the vicinity of the pivot 12are disposed in slots 22 in the segment, the rear ends 15 of the keylevers being disposed in the slots 20.

In the bottom end 18 of each type bar 16, and in front of the pivot 17when the type bar is in the rest position, shown in Fig. 1, there is apart circular recess 23, having its ends open at the side faces of thetype bar and having its axis parallel to the axis of the pivot 17, theperiphery of said recess extending arcuately more than 180 degrees, forexample, approximately 220 degrees.

A similar recess 24 is formed in the rear end 15 of the key lever 11.

A short double-headed dumb-bell shaped link 25 is provided for eachassembly of a key lever 11 and a type 2,818,957 lented Jan- 7, .1958

bar 16. The link has dumb-bell shaped or enlarged part-cylindrical heads26 at each end. The link is disposed between the bottom end 18 of thetype bar and the rear end 15 of the key lever, with one head 26 disposedin the recess 23 and the other head disposed in the recess 24, therelative diameters of a head and the complementary recess being suchthat the head may rotate freely about its axis within the recess butcannot be withdrawn from said recess in a direction radial of said axis.The heads 26 of the link are placed in the recesses 23 and 24 by slidingthem in axially from a side of the type bar or key lever. When the linkis assembled in the key lever and type bar to provide aninterconnection, the bottom end portion of the type bar, the rear endportion of the key lever, and the link are located in a single slot 20of the comb 21, the said slot being of just suflicient width to allow,of operative and return movement of said type bar and key leverportions and of the link without the heads 26 of the link beingdisplaced, axially of the heads and laterally of the slot, from therecesses 23 and 24. The pivot pins or rods 12 and 17 are then placed inposition in the segment 13 and through the type bars and key levers.

Although the slots 22 are separated from the slots 20 in theconstruction described and illustrated, each slot 22 is aligned with aslot 20 and the said two aligned slots in effect form a single slot inthe segment 13 for housing an assembly of key lever 11, type bar 16 andlink 25.

For each type bar there is provided a helical torsion spring 27 which islocated between adjacent key levers, and which has one arm 28 which isdisposed below a top or cover plate 29 above the slots 22 in the segment13 and has a hook 30 on the end of its other arm 31. A connectingtension rod 32 is connected by one end to the type bar 16 through a hole33 in said. bar, and by its other end to the hook 30.

When a key 14 of the machine is depressed, the rear end 15 of the keylever 11 rises and pushes the dumbbell shaped link 25 upward which inturn pushes and throws over the type bar 16 to cause the type on themount 19 to strike the platen 34 (Fig. 2). The spring 27 returns thetype bar 16 to the rest position (Fig. 1) upon release of the key, andthis also effects return of the key lever 11 by reason of the dumb-belllink 25 between the key lever and type bar.

A universal bail 35 is disposed above the rear portions of all of thekey levers 11 and is raised by a said lever when a key is depressed, sothat the usual escapement for allowing traversing movement of a carriagecarrying the platen 34 may be actuated.

In the embodiment shown in Fig. 4, a helical tension spring 36 issubstituted for the torsion spring in Figs. 1 to 3, said tension springbeing anchored by one end in a hole 33 in the type bar 16 and by itsother end to an anchorage 37 on the cover plate 29 of the segment 13.

The embodiment shown in Figs. 5 and 6 employs a link which applies apull or tensile force between the key lever and type bar, as opposed tothe push or compressive force applied by the link 25 in Figs. 1 to 4.The said pull link 38 is substantially of S-formation and has dumb-bellheads 26 engaging recesses 23 and 24 in the bottom end 18 of the typebar 16 and the rear end 15 of the key lever 11, respectively, as inFigs. 1 to 4. When the key 14 is depressed, the rear end 15 of the keylever is elevated, and the link 38 pulls the bottom end 18 of the typebar to cause said type bar to be thrown for the type on the mount 19 tostrike the platen 39 (Fig. 6). When the key 14 is released, the spring36 returns the type bar and the link 38 pulls the key lever 11 back tothe rest position of Fig. 5.

As examples, the platen 39 in Figs. 5 and 6 is of a nonrotatable bartype, whilst the platen 34 in Figs. 1, 2 and 3 is of the usualcylindrical rotatable type; either type of platen may be used with anyembodiment of the invention. The coupling of the key levers to the typebars by means of dumb-bell shaped links results in a considerablereduction in the number of moving parts of the machine, therebyeflecting a saving in weight and allowing the size of the machine to bereduced, and is a convenient way of arranging a simple connection whichwill permit of the large arc of movement required from each type bar.

What I claim and desire to secure by Letters Patent is: A typewriter orlike machine comprising a series of assemblies of key levers and typebars, each assembly including a key lever, a type bar and a link ofdumb-bell shape, the said link connecting the end of the key lever whichis remote from the key thereon to the end of the type bar which isremote from the type thereon, the interconnection between said link andsaid ends of said key lever and type bar being provided by interengagingheads and recesses on the respective members, the said heads beingcylindrical and the said recesses being part circular and open at theiraxial ends, the arc of each of said part circular recesses extendingmore than 180 degrees whereby the said interengaging cylindrical headscan be disengaged therefrom only by relative axial movement, thusensuring that an operative printing or return movement imparted 4 I I toeither the key lever or the type bar of an assembly produces acorresponding movement of the other said element, two pivotal mountingsbeing provided for the key levers and type bars of said assemblies theaxes of which are substantially parallel to the axes of said recesses,and a comb-like housing element for said assemblies, said element havinga plurality of open-ended slots to provide a separate slot for eachassembly, the said pivotal mountings and the link and adjacentinterconnected ends of the key lever and type bar of each assembly beingdisposed and located in a said slot in said comb-like housing element,each said slot being of limited width so as to permit operative printingand return movement of said assembly on its said pivotal mountings whilepreventing undue relative movement of the elements of said assembly indirect-ions parallel to the axes of said pivotal mountings and saidrecesses such as would allow disconnection of said link from said keylever and type bar.

References Cited in the file of this patent UNITED STATES PATENTS

